Rock-drill



2 Sheets--Sheet I.

(No Model.)

T. W. CHAPMAN.

ROCK DRILL.

INVENTOIR T W Cha/37776 ATTORNEY Tu: mams trans co. wnsmusrou. D. c.

(No Model.) 2 Sheets-Sheet 2.

I T. W. CHAPMAN.

110011111111111. No. 541,030. Patented June' 11, 1895.

IN VEN T '0R TW. Cha/aman ATTORNEY vIO line appear in elevation.

iJNirEn STATES PATENT OFFICE.

THERON w. CHAPMAN, on LAKEWOOD, COLORADO.

ROCK-DRI LL.

SPECIFICATION forming part of Letters Patent No. 541,030, dated June.11, 1895.

Application tiled September 17, 1894. Serial No. 523,212. (No model.)

To all whom it may concern:

Be it known that I, THERON W. CHAPMAN, a citizen of the United States of America, residing at Lakewood, in the county of Jefferson and State of Colorado,have invented certain new and useful Improvements in Rock-Drills;

and I do declare the following'to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the'accompanying drawings, and to the figures of reference marked thereon, which form a part of this specilication.

-My invention relates to improvements in rock drills, and consists of the features, arrangements and combinations hereinafter (lescribed and claimed, all of which will be fully understood by reference to theaccornpanying' drawings, in which is illustrated an embodiment thereof.

In the drawings, Figure 1 is a side elevation of the machine. Fig. 2 isa longitudinal section taken on the line as, Fig. 1. Fig. 3 is a section taken on the line e' z, Fig. 1. In this view the mechanism is shown in connection with a sectional column, which is shown partly in section and partly broken away. Fig. 4 is a section taken v on the line 'y y, Fig. 1. The parts to the right of this Fig. 5 is a perspective View of the keeper carrying the lockingdogs. Fig. 6 is a section taken on the line D D, Fig. 5. Fig. 7 is a section taken on the line fu fu, Fig. 3, looking downward.

Similar reference characters indicate corresponding parts in the views.

Let the numeral 5 designate the track rotatably mounted on a pin 6 made fast to one part of a clasp 7. The two parts of this clasp embrace the column. They are connected on one side of the column by a hinge 7a, and on the oppositefside of the column by a bolt 7G. By loosening the clasp 7, the track 5 may be swung around the column horizontally.

The vcolumn Sis, for convenience, composed of sections 8ad of any desired length. These sections are united by slipping their extremities into coupling sleeves 8. The upper section of the column is provided with a threaded aperture in which is inserted a screw 9. The upper extremity of the screw is swiveled in a Aadapted to reciprocate therein.

sort of shoe 10 adapted to engage the upperwall of the tunnel or drift. The column is secured in place by the adjustment of the screw whose head is apertured to receive a pin or bar to be used as a lever.

The track 5 is made fast on the pin 6 by means of a cam-lever 12 whose head is in- 'serted in a recess formed in the track. The

head of this lever is apertured to receive the pin 6 which passes therethrough. The movable frame 13 is mounted and slides upon the track 5. The upper part 13a of this frame is tubular and incloses the hammer 14 which is within this tubular casing, and to the rear of the hammer, is a coil spring 15. The rear extremity of the tubular casing is closed by a screw-cap 16 in which is lswiveled a screw 17 carrying a nut 18 which forms a stop for the rear extremity of the spring 15. By turning the screw 17, the position of the nut thereon is changed, and the tension of the spring regulated at will.

The .tubular part 13a of the frame is divided. In the forward portion of this tube is located the chuck v19. This chuck is provided with a toothed collar 19a, the teeth of which lie successively in the path of one of Located also.

theI rotating cams, whereby the partial rotation between strokes is imparted to the drillbit 20 during the operation of the machine. The rear extremity ot'4 the drill-bit projects through the chuck and is exposed to the blows of the hammer. The rear extremity of the chuck is recessed to receive a rubber cushion 19c`to break the force of the hammers blow in case the drill reaches a natural hole or cavity in the rock and slips 'through the chuck, thus exposing the latter to the blow of the hammer. The chuck is provided with a screw-cap 19d in which is inserted .a screw which projects into a groove formed in the drill-bit, whereby the chuck and bit are made to rotatetogether.

Journaled in the movable frame above 'the tube 13' is a shaft 2l carrying the S-shaped` cams 22. To this cam-shaft is attached a crank whereby the shaft may be rotated by hand. As the shaft 'turns in the direction indicated by the arrow, the cams engage proj ections 14.a formed on the hammer and force the latter backward against the coil-spring IOO 15. As soon as the cams release the hammer, the latter is driven forcibly'forward by the recoil of the spring, against the drill-bit. As the hammerl is making its backward stroke, one of the cams engages the toothed collar 19a on the chuck and gives the latter, together with the drill-bit, the partial rotation between strokes as heretofore mentioned. The tubular casing 13 is provided wi-th slots 13c through which the lugs or projections 14' of the hammer protrude. The slots are ol' a length equal to that of the stroke ot the hammer.

Fnlcrumed in the movable frame below the tubular part, is a bell-crank lever 2l one arm of which lies in the path of one of the projections 14.a as the hammer is making the forward movement, while the epposite arm engages a lug 25 formed on a block or keeper 25 pivoted on the movable frame and carrying vertically7 movable, spring-actuated dogs 26. The lower extremities of, these dogsengage a toothed rack 5 attached to the track, while their upper (Xtremities protrude from the top of the keeper and are provided with pins 26a. Movably attached to the top of the keeper and adapted to engage the pins 26 from below is a key 27, the normal position of which is such that it does not interfere with the function of the dogs. On this key are formed cams or raised parts 27'a whereby by sliding the key forward, these raised parts engage the pins and draw the dogs upwardly sufficiently to disengage the latter from the toothed rack 5a whereby the movable frame may be quickly moved backward on the track after it has reached its forward limit of movement thereon. y

The dogs 26 are shouldered,and the keeper is recessed to receive them. ln these recesses above the shoulders are located the coil springs 26C which bear against the shoulders of the dogs below, and the top walls of the recess above.

To the rear of the keeperis located an auxiliary locking pawl 28 pivoted on the movable fratne 13 and engaging the toothed rack.

From the foregoing description, the operation of the machine will be readily understood. As the cam-shaft is rotated, the cams engage the projections 14 on the hammer and give the latter its backward movement, placing the spring 15 under tension. AS soon as the hammer is released the recoil of the spring forces the hammer forward against the drillbit. This forward movement of the hammer also engages the bell crank lever 24: and feeds the movable frame forward as the drill moves into the rock. As one arm of the bell crank lever is engaged by the projection on the hammer, the other arm raises the forward eX- tremity of the keeper, which is thus carried forward, allowing the dogs, as soonv as the keeper is released, to drop into the rack a tooth in advance of their former position. It will thus be seen that the movement of the frame 13 keeps up with the progress ot the drill.

Having thus described my invention, what I claim is- 1. In a rock drill, the combination of the track having the movable frame mounted thereon and provided with a tubular casing, a spring-actuated hammer located within the casing, a chuck also located within the casing and carrying the drill-bit, a shaft carrying cams adapted to engage projections on the hammer protruding through slots formed in the casing, and suitable feed mechanism composed of a bell crank lever, a collar pivoted on the frame and carrying vertically oscillating,r dogs whose upper extremities project above the keeper and carry pins, a key applied to the `top of the keeper and adapted to engage the pins and raise the dogs from the track, a toothed rack on the track which the dogs cngage, the keeper being also provided with a lng which engagesone arm of the bell crank lever, the other arm of which lies in the path of the projection on the collar, substantially as described.

2. In a rock drill, the combination with the track carrying the toothed rack, of the movable frame mounted on the track and having a tubular casing, an oscillating hammer located within the tubular casing, a chuck also located in the casing and carrying the drill which occupies a position in the path of the ham mer, a bell crank lever fulcru med in the movable frame and having one arm occupying a position in the path of a projection on the hammer, a keeper pivoted on the movable frame and carrying an oscillating dog engaging the toothed rack, the upper extremity ol the dog projecting above the keeper, and suitable means applied to the top of the keeper for raising the dog from engagement with the rack, the keeper being also provided with a projection which liesin the path of one arm of the bell crank lever as the latter is actuated, snbstantially as described.

3. In a rock drill, the combination with the track and movable frame, of the oscillating hammer mounted on the movable frame, the drill chuck also mounted in the movable frame inline with the hammer, the bell crank lever, the keeper pivoted on the frame and carrying vertically reciprocating-spring-actuated dogs whose upper extremities project above the keeper and carry "pins, a key applied to the top of the keeper and adapted to engage the pins and raise the dogs from the track, a toothed rack on the track which the dogs engage, the keeper being also provided with a lug which engages one arm of the bell crank lever, the other arm of which lies in the path ot a projection on the hammer, substantially as described.

4. In a rock drill, the combination of the track and movable frame having the tubular casing, the hammer located in said casing and provided with projections protruding through ICO 541,030 A el slots formed therein, a coil spring located in the casing to the rear of the hammer, a tension screw journaled in the. rear end of the casing and carrying a nut engaging the spring, a chuck located in the casing and carrying the drill-bit exposed to the hammer, the chuck being provided with a toothed collar, the shaft journaled in the movable frame and carrying cams adapted to engage the projections on the hammer While one of the cams engages the toothed collar' and gives the drill-bit and chuck the partial rotation between strokes,

and suitable feed mechanism, composed of a 5. Ina rock drill, the combination of the track having the toothed rack, the movable frame mounted thereon, the hammer, the spring engaging the hammer, the chuck, the drill-bit located therein, the shaft carrying the cams engaging projections on the hammer, one of said cams engaging a toothed collar formed on said chuck, a bell crank lever 'actuated from the hammer, and a keeper carrying an oscillating dogengaging the toothed rack and having a lug engaging one arm of the bell crank lever, said dog projecting above the keeper and carrying a pin, a key applied to the top of the keeper and adapted to engage the pin of the dogand raise it from the toothed rack, substantially as described.

In testimony whereof I affix my signature in the presence of two Witnesses.

THERON W. CHAPMAN. Witnesses:

CHAs. E. DAWSON, AGf. J. ROLLANDET. 

